Printing ink pump

ABSTRACT

The pump for feeding printing ink in controllable amounts to the ink motion of a printing machine consisting of a block-like cylinder which has an axially extending bore and which has one slanted front face. A piston is rotatably and axially reciprocating in the bore. The piston has a flat on one end which cooperates with an intake and a discharge bore perpendicularly disposed in the cylinder block with respect to the axial bore therein. The piston is rotated by a gear fixedly attached to the piston and is axially moved by a slider which is attached to the gear and which is kept in sliding contact at the slanted front face of the cylinder under the force of a helical compression spring acting axially on the piston. A rod is axially movable in the bore of the cylinder for controlling the length of the reciprocating stroke of the piston by way of an adjusting screw.

United States Patent [191 Fusco Oct. 21, 1975 PRINTING INK PUMP [76] Inventor: Ralph L. Fusco, 30 Fern Drive,

Commack, NY. 11725 [22] Filed: Dec. 17, 1974 [21] Appl. No.: 533,478

[52] US. Cl 417/500; 101/365 [51] Int. Cl. F04B 7/06; F04B 37/10; B41F 31/02 [58] Field of Search 417/500; 137/5651, 565.2;

Primary Examiner-C. J. Husar Assistant Examiner-Richard E. Gluck [5 7 ABSTRACT The pump for feeding printing ink in controllable amounts to the ink motion of a printing machine consisting of a block-like cylinder which has an axially extending bore and which has one slanted front face. A piston is rotatably and axially reciprocating in the bore. The piston has a flat on one end which cooperates with an intake and a discharge bore perpendicularly disposed in the cylinder block with respect to the axial bore therein. The piston is rotated by a gear fixedly attached to the piston and is axially moved by a slider which is attached to the gear and which is kept in sliding contact at the slanted front face of the cylinder under the force of a helical compression spring acting axially on the piston. A rod is axially movable in the bore of the cylinder for controlling the length of the reciprocating stroke of the piston by way of an ad justing screw.

7 Claims, 3 Drawing Figures U.S. Patent Oct. 21, 1975 PRINTING INK PUMP BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to fluid feeding valveless piston pumps having a stroke of a controllable length for adjusting the metering of the amount of feeding. The invention relates particularly to pumps for pumping printing ink in controllable amounts to the ink motion of a printing machine for applying of the ink to the printing plates on the plate cylinder of the printing machine.

2. Description of the Prior Art Pumps for feeding fluids including printing inks to ink motions of printing machines have been proposed combinations of gears, pistonand vane pumps in a great variety of forms, including the well-known sliding plates, wobble plates, cranks, eccentrics, slide blocks and others. Typical pumps of these characteristics have been known from US. Pat. Nos. 1,214,856, 1,311,198 and 1,348,900 (sliding plate); 1,744,741 (wobble plate; 3,065,693 (cam-operated piston) and valveless pumps with pistons which are rotated and reciprocated simultaneously by various mechanism, such as U.S. Pat. No. 2,450,570. While pumps of these prior art patents have been used for various purposes, it has been one known problem with feeding of printing ink in small, adjustable amounts, to seal the operating elements and to prevent wear thereof since printing inks are not really true liquid fluids but consist of certain kinds of finely dispersed solids suspended in oils, mostly mineral oils, and having a more or less substantial viscosity. Another problem was the rate of filling of the pump cylinders during the suction stroke, which caused difficulties of precise metering of the printing ink to the ink motion for inking appropriately the printing plates of the printing machine. Positive displacement pumps such as disclosed in the US. Pat. No. 3,366,051 have been successfully used in practice but are of a complicated structure and cause problems of high precision in manufacturing.

It is the aim of this invention to solve the indicated problems.

SUMMARY The invention consists in such novel features, construction arrangements, combinations of parts and improvements as may be shown and described in connection with the apparatus herein disclosed by way of example only and as illustrative of a preferred embodiment. The pump has a minimum of operating parts and has a cylinder block with one straight bore extending longitudinally therethrough. The piston of the rotating and reciprocating type is disposed in this bore and it is obvious that these parts can easily be manufactured with high precision. The piston is rotated by means of a gear fixedly attached thereto. The cylinder block has a slanted end face adjacent the gear, the angle of the inclination of the slant being disposed to provide a difference of height between the low point and the high point equalling the maximum length of the reciprocating stroke of the piston. A slider stud is press-fitted in the web of the gear, which stud is located in the latter in such manner, that it rides with its rounded end on the slanted end face of the cylinder. Thus the piston makes one reciprocating movement for one revolution thereof. The end of the piston is held in an antifriction bearing, the outer race of which is held in a nonrotating reverse cup. A helical compression spring is arranged in an axial relationship to the piston and abuts with one end against the reverse cup, whereas the other end is located in a suitable manner in the wall of the housing in which the cylinder block is located. Thus the spring force provides the constant contact between the stud on the gear and the slanted end face of the cylinder block, whereby the actual discharge stroke of the piston is performed. The piston has the known flat side on the delivery end, and the cylinder has the intake and discharge port holes perpendicularly bored to the cylinder bore, in the proper relation to the delivery end of the piston.

A non-rotating rod is slidably fitted in the bore of the cylinder. The axial position of the rod is determined by an adjusting screw which can be operated either by hand or by remotely controlled motorized means. The end of the rod is abutted by the discharge end of the piston; and it can push for the purpose of adjusting the length of the intake stroke of the piston, the latter against the force of the helical spring by lifting the slider stud partially off the slanted cylinder end face. When the piston is so far pushed back that the slider stud is no longer in contact with the slanted face, the gear with the piston is only rotating but no longer reciprocating, and the delivered amount becomes zero.

Objects and advantages of the invention will be set forth in part hereafter and in part will be obvious herefrom or may be learned by practicing the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

It is an object of the invention to provide a valveless pump for feeding adjustable, metered amounts of printing ink to the ink motion of a printing machine.

It is a further object of the invention to provide a valveless pump of the kind described which comprises a minimum amount of movable parts.

Furthermore it is an object of the invention to provide a pump which has very simple yet effectful adjustment means for varying the amount of discharge from zero to a maximum in infinite increments.

Another object of the invention is to provide a pump ofa very compact structure which can be economically manufactured with high precision.

Yet another object of the invention is to provide a pump of the kind described which can be assembled in multiples thereof for forming complete aggregates for printing machines whereby all pumps of the aggregate are driven simultaneously by one single gear train.

Various further and more specific purposes, features and advantages will clearly appear from the detailed description given below taken in connection with the accompanying drawing which forms part of the specification and illustrates merely by way of example one embodiment of the device of the invention.

BRIEF DESCRITPION OF THE DRAWING In the following description and in the claims, parts will be identified by specific names for convenience, but such names are intended to be as generic in their application to similar parts as the art will permit. Like reference characters denote like parts in the several flgures of the drawing, in which FIG. 1 shows, partly sectioned, a side elevation of the pump of the invention;

FIG. 2 shows a plan view of the pump; FIG. 3 shows a section of aportion of the pump, partly broken away, taken along the line 3-in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in more deteil to the drawing illustrating a preferred embodiment by which the invention may be realized, there is in FIGS. I and 2 a cylinder block 11, which is attached by bolts 12 to the bottom of a housing 13. Cylinder block 11 has a bore 14 longitudinally extending therethrough. One end face 15 of cylinder block 11 is machined off at an angle to the centerline of bore 14, thus providing a slanted plan on the end of cylinder block 11. A piston 16 is fitted in bore 14 for a combined rotary and reciprocating movement therein. Piston 16 has a flat side 17 at the free end thereof. An intake bore 18 and a discharge bore 19 are provided on cylinder block 11 at right angle of bore 14. Bore l8 and bore 19 are disposed to cooperate with flat side 17 of piston 16. A gear 20 is fixedly attached at the other end of piston 16, which is rotatably held in an antifriction bearing 21. The outer race 22 'of bearing 21 is lodged in a reverse cup 23, which also supports one end of a compression spring 24. A cap 25 is bolted on the wall of housing 13, which holds the other end of spring 24 in place.

A slider stud 26 is press-fitted in the body of gear 20 in such manner that the rounded head 27 of stud 26 is sliding on slanted end face 15 of cylinder block 11 and is kept in contact thereon by the force of spring 24. Thus, piston 16 is reciprocated in bore 14 whereby the suction stroke is performed by rounded head 27 of stud 26 sliding on slanted end plan 15, and the discharge stroke is forced by the action of spring 24. The force of spring 24 is sufficient for feeding the printing ink under pressure to the ink rollers or through appropriate orifices ofa conventional ink rail. The elastic force provides also for the safety against breaking pipe lines or other parts if an obstruction in the discharge line would occur.

A rod 30 is fitted in bore ;4 with the same sliding tolerance as piston 16. A spring plate 31 is fitted on rod 30 and a plurality of compression springs 32 are located in holes 33 of cylinder block 11 for abutting against spring plate 31. An adjusting screw 34 is threated in a threaded block 35 which is attached to the inside wall of housing 13. Screw 34 abuts against the end of rod 30 and has a knurled knob 36 fixedly attached at the end of screw 34 which protrudes over the outside wall of housing 13.

The pump works as follows:

Gear 20 is driven by a driving gear 37 and rotates piston 16. Since stud 26 slides with its head 27 on slanted face 15, piston 16 moves reciprocatingly in bore 14 at the same time. The angle of slant of end face 15 is obviously determining the maximum length of the stroke of piston 16. When the position of rod 30 in bore 14 is adjusted by screw 34, it pushes piston 16 outwardly whereby rounded head 27 of stud 26 gets out of contact with slanted end face 15 to a desired degree. Thereby the intake stroke of piston 16 is decreased and so is the discharge amount of the pump. When rod 30 is ultimately adjusted so that it pushes piston 16 so far back that rounded head 27 of stud 26 gets entirely out of contact with slanted end face 15, no reciprocating stroke of piston 16 takes place and the discharge of the pump becomes zero. It can be easily seen that a preci sion control of the amount of discharged printing ink is possible within the range between the maximum which is determined by the slant of the end face of the cylinder block, and zero.

It is obvious that any desiredplurality of individual cylinder blocks can be arranged in side-by-side relationship in a correspondingly large housing 13, as'the case may be for a large printing machine whereby all pumps are driven by one driving gear 37 and having all gears 20 of the individual pumps in mesh with one another. It is also understood that knob 36 can be replaced by motorized means (not shown in the drawing) and by remote control. 1

While the invention has been described and illustrated with respect to a certain preferred example, which gives satisfactory results it will be understood by those skilled in the art after understanding the principle of the invention, that various other changes and modifications may be made without departing from the spirit and scope of the invention.

What I claim as my invention is:

1. A valveless positive displacement pumphaving a cylinder block, said cylinder block having a longitudi: nal bore therethrough and an intake and a discharge bore disposed perpendicularly of said longitudinal bore, and a piston disposed to rotate and simulta. neously to reciprocate in said longitudinal bore, said piston having a flat side at the free end thereof,said flat side disposed tocooperate with both said intakeand said discharge bores, respectively, said pump including a slanted end face on said cylinder block, a gearfixedly attached at the other end to said piston for rotatively driving said piston, said gear having a slider stud attached thereon, said stud disposed to be in a sliding engagement with said slanted fa'ee-ofsaid cylinder block, first means disposed at said other end of said piston to supply a pressure to said pistonin an axial direction, and a non-rotatable rod axially slidable in said bore, said rod abutting at said free end of said pistomand second means disposed to adjust the position of said rod in said bore for controlling the length of the intake stroke of said piston.

2. A valveless positive displacement pump according to claim 1, and an antifriction bearing disposed at said other end of said piston in proximity of said gear to support said other end.

3. A valveless positive displacement pump according to claim 1, said slider stud having a ball-shaped head in sliding engagement with said slanted end face.

4. A valveless positive displacement pump according to claim 2, including a housing surrounding a clylinder block said first means comprising a helical compression spring lodged at a wall of said housing, said spring disposed to provide the axial force for the discharge stroke of said piston and to keep said slider stud in said sliding engagement with said slanted end face of said cylinder block.

5. A valveless positive displacement pump according to a claim 4, said antifrictionbearing having a nonrotating outer race, and a reverse cup providing the support for said outer race.

6. A valveless positive displacement pump according to claim 5, said helical compression spring disposedto abut at said reverse cup and to apply an elastically yielding force at said reverse cup.

ing, said screw means abutting at the end of said rod,

' and a plurality of compression springs disposed to keep said rod in continuous axial contact with said adjustable screw means. 

1. A valveless positive displacement pump having a cylinder block, said cylinder block having a longitudinal bore therethrough and an intake and a discharge bore disposed perpendicularly of said longitudinal bore, and a piston disposed to rotate and simultaneously to reciprocate in said longitudinal bore, said piston having a flat side at the free end thereof, said flat side disposed to cooperate with both said intake and said discharge bores, respectively, said pump including a slanted end face on said cylinder block, a gear fixedly attached at the other end to said piston for rotatively driving said piston, said gear having a slider stud attached thereon, said stud disposed to be in a sliding engagement with said slanted face of said cylinder block, first means disposed at said other end of said piston to supply a pressure to said piston in a axial direction, and a non-rotatable rod axially slidable in said bore, said rod abutting at said free end of said piston, and second means disposed to adjust the position of said rod in said bore for controlling the length of the intake stroke of said piston.
 2. A valveless positive displacement pump according to claim 1, and an antifriction bearing disposed at said other end of said piston in proximity of said gear to support said other end.
 3. A valveless positive displacement pump according to claim 1, said slider stud having a ball-shaped head in sliding engagement with said slanted end face.
 4. A valveless positive displacement pump according to claim 2, including a housing surrounding a clylinder block said first means comprising a helical compression spring lodged at a wall of said housing, said spring disposed to provide the axial force for the discharge stroke of said piston and to keep said slider stud in said sliding engagement with said slanted end face of said cylinder block.
 5. A valveless positive displacement pump according to a claim 4, said antifriction bearing having a non-rotating outer race, and a reverse cup providing the support for said outer race.
 6. A valveless positive displacement pump according to claim 5, said helical compression spring disposed to abut at said reverse cup and to apply an elastically yielding force at said reverse cup.
 7. A valveless positive displacement pump according to claim 1, including a housing surrounding a cylinder block said second means disposed to adjust axially the position of said rod, said second means comprising a manually adjustable screw means at a wall of said housing, said screw means abutting at the end of said rod, and a plurality of compression springs disposed to keep said rod in continuous axial contact with said adjustable screw means. 